As shown in FIG. 11 and FIG. 12, a prior art locking device for doors and windows generally comprises:
a base member "A" which can be fixed on a door or window at a location near an edge thereof, the base member "A" being furnished with an elongated sleeve "A2" which has an axially extended hole "A1" penetrating therethrough, the sleeve "A2" being formed with an elongated guiding groove "A3" and at least one notch "A4" at one end of the guiding groove "A3" on the outer surface of the sleeve "A2"; PA1 a locking shaft "C" being received by the hole "A1" and being slidable along the hole "A1", the locking shaft "C" connecting with a handle "C1" by means of screw, the handle "C1" extending out of the guiding groove "A3" and being movable therealong such that the handle "C1" can be received by the notch "A4" when the handle "C1" is moved to one end of the guiding groove "A3"; PA1 a shaft receiver "B" having a shaft hole "B1" and being fixed on a frame "D" of the door or window at a place corresponding to the base member "A", by pushing the handle "C1" to make the locking shaft "C" moving along the hole "A1", the front end of the locking shaft "C" will plug into the shaft hole "B1" of the shaft receiver "B" so as to achieve the function of locking the door or window on the frame "D". PA1 (1) During operation, firstly the user has to lift up the handle "C1" by his/her finger to make the handle "C1" rotate to leave the notch "A4", then push the handle "C1" sliding along the guiding groove "A3" to make the locking shaft "C" move along the hole "A1". Such an operation is not very handy. PA1 (2) When the door/window is open (i.e., unlocked from the frame "D"), the front end of the locking shaft "C" is still very easy to extend out of the sleeve "A2". As a result, both the locking shaft "C" and the shaft receiver "B" are very easy to be damaged due to the impact between them when the door/window is closed again (as shown in FIG. 12).
However, the above described prior art has the following deficiencies: